DE102008030788A1 - Method for cleaning vacuum pumps - Google Patents

Abstract

Vacuum pumps have pumping elements arranged in a pump chamber formed by a housing. Contaminants accumulate on the pumping elements and on the walls of the pump chamber. To clean the vacuum pump, a container having a cleaning fluid is connected to the suction chamber. Furthermore, a control device is provided, which is connected to at least one sensor element. At least one pump parameter is detected with the aid of the sensor element and transmitted to the control unit for further processing. For further processing, the control unit has a monitoring program. By the monitoring program, a cleaning program is triggered in response to at least one stored in the control unit triggering parameters, the cleaning program in particular time and / or quantity-controlled cleaning fluid feeds the pump chamber and automatically repeats the process if necessary. The cleaning fluid can be used until exhausted. Furthermore, filtering of the cleaning fluid of solids is possible.

Description

The The invention relates to a method for cleaning vacuum pumps.

With Help of vacuum pumps, for example, to carry out Coating, drying and sintering processes gases, in particular Air, aspirated from coating chambers or the like. The sucked off Depending on the application, gases contain a different amount of particles. Such contaminants are deposited in the pump chamber of the vacuum pump on the Inside of the pump chamber forming housing and / or at the pumping elements. In such processes are usually used dry vacuum pumps. These are, for example to screw pumps, rotary vane pumps, Roots pumps or correspondingly suitable, in particular dry vacuum pumps. The vacuum pumps always have a suction chamber, in which the pumping elements such as the screws, the slide or the Roots are arranged.

Around damage it is necessary to avoid the vacuum pump due to soiling the impurities at the scoop space walls and to remove at the pumping elements. This often requires to dismantle the pump and the pumping elements from the pump chamber to to remove the impurities then mechanically. Such cleaning of the vacuum pump is time consuming and costly. It is also necessary to interrupt the process for a longer period of time or to replace the pump to be cleaned by a corresponding pump. This assumes that a corresponding number of replacement pumps which increases the cost of the manufacturing process.

Further it is known the scoop space by means of a cleaning fluid to clean. For this purpose, the vacuum pump is disconnected from the process and a small amount of cleaning fluid the scoop space fed. Because of in the scoop space prevailing low pressure and a direct evaporation the cleaning fluid. By the occurrence of cavitation is a blasting or removal the contamination from the inner wall of the pump chamber or from the pumping elements. To carry out This cleaning process requires that a correspondingly lower Pressure in the pump chamber prevails.

The Starting such a cleaning process is done manually, wherein while the cleaning process a predetermined amount of detergent, For example, one liter per minute is supplied to the pump chamber. For this purpose, the associated with a reservoir for the cleaning fluid Supply line, which serves to supply the cleaning fluid to the pump chamber, a shutter on. The cleaning process, for example, then started by a user when he receives a corresponding warning signal obtained from the vacuum pump. For this purpose, the vacuum pump is usually provided with a vibration sensor that exceeds a limit value generates a warning signal. Furthermore, regardless of the actually occurring Pollution always the same cleaning process. This leads to, that to make sure that the vacuum pump is actually from Pollution is cleaned, a time-consuming cleaning process carried out becomes. this leads to to a relatively long stoppage of production as well as to one increased Consumption of cleaning agent, combined with the disposal costs for used Cleaning supplies.

task The invention is a method for cleaning vacuum pumps to create that is more effective and thus more economical.

The solution The object is achieved according to the invention by a method for cleaning of vacuum pumps according to claim 1.

The with the inventive method cleaning vacuum pump has pumping elements in a housing forming a pumping chamber. The pumps to be cleaned are in particular screw pumps, Rotary vane pumps, Roots pumps, or correspondingly suitable, in particular dry, vacuum pumps. at The pumping elements are thus, for example, helical rotors. Slide or Roots Piston, those in the scoop space are arranged. The scoop space is with at least one container connected to provide a cleaning fluid. Here can the cleaning fluid is a cleaning fluid, a cleaning gas or a corresponding mixture. Further is the vacuum pump to be cleaned with at least one sensor element connected, wherein the sensor element connected to a control device is.

According to the inventive method, at least one pump parameter is first detected by the at least one sensor element and transmitted to the control device. In the control device, further processing of the at least one pump parameter takes place in a monitoring program stored in the control device. In addition to the monitoring program, at least one tripping parameter is stored in the control device. The monitoring program processes the at least one pump parameter and triggers in dependence on the at least one trigger parameter, which is, for example, is a threshold or threshold, a cleaning program. By the cleaning program is carried out in particular a time- and / or quantity-controlled feeding of cleaning fluid to the pump chamber.

One substantial advantage of the method according to the invention for cleaning of vacuum pumps is that automatically depending on Pump parameters and tripping parameters Cleaning program is started. A manual feeding of Cleaning fluid for example by manual opening a valve is not required. Furthermore, it is by provision a particular computer-controlled cleaning program possible, this individually, in particular depending on the gas to be pumped adjust and adjust. In this case, the setting is preferably carried out and / or customizing the cleaning program to the current situation automatically.

About suitable As a pump parameter, sensors can preferably be the temperature of individual components the vacuum pump are detected. For example, the temperature of the housing, the pumping elements and / or the drive motor are detected. Further can the temperature of a coolant, such as, for example, the pumping elements cooling oil or the pump in particular the pump housing cooling Air flow to be determined. By providing appropriate sensors may also be the temperature of the pumped gas, in particular at the pump room inlet and / or at the pump chamber outlet be measured. The measured by the corresponding sensor elements Temperatures are transmitted to the control device for further processing.

By Another sensor device, it is possible, the vibrations or Vibrations of the individual components of the vacuum pump by means of To measure vibration sensors. This can in turn in turn the vibration or vibration of the housing, the pumping elements and / or be measured of the drive motor.

Of Furthermore, it is advantageous to measure gas pressures as pump parameters. These may be pressures the pumped gas, in particular at the suction chamber inlet and / or on the Pump chamber outlet act. Furthermore, it is possible to have one To measure sealing gas pressure, provided that the vacuum pump for sealing for example, the scooping room across from a transmission chamber sealing gas is used. It is also possible to use the Coolant pressure to eat.

at a particularly preferred embodiment The power consumption of the pump motor is measured and used as a pump parameter transmitted to the controller for further processing.

The explained above Parameters can be processed individually. Preferred is a combination of the measured Pump parameters, in particular individual or all those listed above Pump parameter determined and by means of the monitoring program in the control device be further processed. In particular through the combination of selected pump parameters can be extremely accurate Diagnosis of the degree and type of contamination in the vacuum pump respectively. It is particularly preferred that several pump parameters be linked together on the basis of a diagnostic model. In this case, the diagnostic model in particular a mathematical Have algorithm.

In dependence of the diagnostic result in conjunction with the deferred tripping parameters it then possible in a particularly preferred embodiment, a select appropriate cleaning program to one possible to allow effective cleaning of the vacuum pump. This can, for example also a pre-selection can be made manually and / or individual Program components of the cleaning program made by the user become.

In a further, particularly preferred embodiment of the method according to the invention, measurement of at least one pump parameter also takes place during the course of the cleaning program, which may be the same pump parameter measured for diagnosis. However, it is also possible to measure other pump parameters or only part of the pump parameters used for the diagnosis. By a corresponding measurement of pump parameters during the course of the cleaning program and a corresponding further processing in the monitoring program, possibly on the basis of another or modified diagnostic program, the cleaning process can be controlled. For this purpose, if necessary, a separate monitoring program or a separate software deposited. It is thus possible, for example, by depositing a cleaning model in the control device, to check directly during the cleaning process already the effect of cleaning. This can significantly increase the effectiveness. In particular, the cleaning process can be terminated as soon as it is determined that the contaminants are already removed. As a result, the average duration of the cleaning processes can be significantly reduced. Furthermore, it is possible during the cleaning process in Dependence of the determined pump parameters, for example, supply additional cleaning liquids to remove hard-to-remove contaminants and / or to repeat the cleaning process.

Further it is preferred that a cleaning liquid and additionally a Cleaning gas is used. The cleaning fluid is mixed with the cleaning gas preferably mixed prior to entry into the pump chamber, wherein the mixing ratio preferably in dependence the results of the monitoring program is controlled.

Of Further, it is preferable to use different cleaning liquids to provide, the cleaning liquids preferably in different containers to be provided. This has the advantage that in particular while the cleaning process individual cleaning liquids are added can, or the mixing ratios can be adjusted. In particular, chemical, biological and / or organic cleaning fluids provided. As cleaning fluids for vacuum pumps are dependent of the subsidized Gases, especially citric acid, basic, acidic, o the neutral solvent suitable. Especially It is advantageous to alternately organic and aqueous cleaning fluids to use. This has the particular advantage that, for example when rinsing with good cleansing, non-volatile and then rinsing with volatile Cleaning agent possible is to be a reliable one and to ensure quick drying.

In addition to the cleaning fluid In particular, several cleaning gases are provided, which in turn in different containers can be held. The cleaning gases may be, for example, nitrogen act. This is particularly advantageous because nitrogen is also called Block gas is used and in that respect to the corresponding plant already a nitrogen storage tank is available. This is due to the fact that nitrogen too used as gas ballast. As cleaning gases in particular also fluorine and fluorine compounds and active gases can be used.

Especially in the determination according to the invention and consideration several pump parameters during further processing in the monitoring program A good diagnosis of the pollution can be realized become. Dependent on the diagnosis result and the corresponding in the control stored trigger parameters can then start a pollution-specific cleaning program become. By taking place in the preferred embodiment of the invention Measurement of the same, further or part of the pump parameters even while of the cleaning process, this can be regulated, so that the Effect of cleaning is immediately taken into account. hereby is a much more reliable Cleaning the vacuum pump possible with less time.

Especially it is preferred to use the cleaning medium several times. Especially can be a cycle for the cleaning fluid may be provided. This represents a considerable Cost savings, since effective cleaning fluids are often expensive. It is particularly preferred in this case, the cleaning fluid after the Flow through the scoop space again the container supply. Preferably, before returning the Cleaning fluids in the supply container, a cleaning of the cleaning fluid in particular of solids, this means dissolved Impurities. To further increase the degree of automation is it is advantageous to use the filter element for filtering the solids to provide a sensor which detects when a cleaning or replacing the filter element is required. At the sensor For example, it may be a pressure sensor that detects the pressure drop across the Measures filter element. Dependent on the pressure drop, for example, a signal can be generated as soon as the filter is added, or soiled.

Of Further, it is preferable to improve the quality of the cleaning fluid in particular to continuously check a sensor. This represents another increase the degree of automation, since in turn generates a warning signal can be when replacing the cleaning fluid required is. A corresponding sensor could be arranged for example in the staging container. It can these are commercially available sensors, like infrared sensors to measure contamination, etc. Even sensors that absorb the acid or base content can measure be provided depending on the application.

following the invention will be described with reference to a preferred embodiment closer to the adjacent drawing explained.

The schematically illustrated vacuum pump device has a vacuum pump 10 on, which is a screw pump in the example shown. An inlet 12 the vacuum pump 10 is over a pipeline 14 connected to a room, not shown, to be evacuated, such as a treatment room. An outlet 16 The vacuum pump is via a pipeline with a gas / liquid separator 18 connected. This is with a gas outlet 20 , as well as with a liquid outlet 22 Mistake. The pump to be pumped Gas thus flows as through the arrows 24 represented by the vacuum pump 10 ,

In operation of the vacuum pump 10 Impurities are deposited on the walls of the pump chamber formed by the housing. Furthermore, impurities settle on the pumping elements arranged in the pumping chamber, such as the screw rotors.

Via a gas supply line 26 is, at least one bearing of the vacuum pump 10 for the supply of sealing gas with a gas tank 28 connected. In the line 26 is a barrier gas valve 30 arranged. The sealing gas is usually supplied to a seal between the pump chamber and the gear compartment or the engine compartment in order to prevent penetration of the pumped gas / vapor into the gear compartment and thus an accidental escape from the vacuum pump. This is especially necessary for toxic or explosive gases / vapors.

Furthermore, with the suction chamber of the vacuum pump 10 another gas supply line 32 connected. About this supply line, which also with the gas tank 28 connected to the pump chamber gas ballast can be supplied. In the supply line 32 is a gas ballast valve 34 arranged.

Around the cleaning process according to the invention carry out to be able to Preferably, a plurality of sensor elements are connected to the vacuum pump.

This is in particular a vibration sensor and one or more temperature sensors. Furthermore, pressure sensors may be provided, which preferably the gas pressure at the suction chamber inlet 12 as well as at the pump room outlet 16 measure up. Furthermore, further sensor elements may be provided for determining further pump parameters.

The measured pump parameters are via electrical lines 36 to a control device 38 transmitted. Another pump parameter, which is determined in a particularly preferred embodiment, is the current consumption of a motor driving the pump 40 , The measured current consumption is via an electrical line 42 also transmitted to the control device. With the help of one in the control device 38 provided monitoring program, which is based in particular a diagnostic model, there is a further processing of the pump parameters. Depending on at least one of the control device stored triggering parameters is by the control device 38 triggered a cleaning program. Depending on the triggered cleaning program, a liquid supply valve 44 as well as a gas valve 46 regulated. The liquid supply valve is in a liquid line 48 arranged with a liquid container 50 connected is. About the fluid line 48 and over the pipeline 14 Cleaning liquid is supplied to the pumping chamber of the pump. The liquid is additionally via the gas valve 46 Mixed with gas. This is the gas valve 46 over a line 52 with the gas container 28 connected.

It is preferred, in addition to the illustrated liquid container 50 provide several liquid containers with different cleaning liquids. The provision of several gas containers is preferred. About the controller 38 can then take place a possible mixing of the individual fluids and an individual control of the valves in response to a cleaning program. It is further preferred that pump parameters continue to be detected during the cleaning process, so that the cleaning process can be adapted to the cleaning progress.

This during the cleaning process by the vacuum pump 10 conveyed medium is in the gas / liquid separator 18 separated so that the gas through the gas outlet 20 and the liquid through the outlet 22 in a line 54 flows. By means of a feed pump 56 the separated liquid is returned to the liquid container 50 conveyed back. As a result, an economic recycling of the cleaning liquid can be realized. It is possible to use the cleaning liquid until a cleaning effect due to changes in the cleaning liquid can not be achieved. To measure the quality of the cleaning fluid can within the container 50 a corresponding sensor may be provided.

In the flow direction before or after the pump 56 can be a filter element 57 be arranged to filter out solids, such as dissolved impurities. With the aid of a pressure sensor arranged above the filter element 59 can cause a pressure drop across the filter element 57 be measured. As a result, for example, a warning signal can be generated in a simple manner, as soon as the filter element 57 replaced or cleaned.

To start the outlined in the accompanying figure device is first operating the main switch to power the corresponding components and then opening the valve 30 , Subsequently, all existing sensors are activated. One at the pump 12 the suction side (not shown) provided valve remains closed, whereas the pressure-side valve, if it is present, is opened. Subsequently, the pump 10 started and at the same time the valve 34 open. The set sensor values, which are made according to a possibly stored table, are in the normal range when the device is running properly. This is followed by a warm-up of the pump 10 over a range of about 15 to 30 minutes.

After warming up, the process can be switched on. This is done by the suction-side valve of the pump 10 is opened.

A scheduled or due to a required cleaning short-term shutdown of the pump is done first by closing the suction side valve of the pump. The pump 10 runs with opened valves 34 . 30 continue for about 15 to 30 minutes. After approx. 30 to 40 minutes, depending on the design, the pump is switched off 10 , At the same time, if available, an exhaust valve is closed. While the suction-side valve remains closed, the valves close 30 . 34 , The pump is now back in a starting position.

Alternatively, when switching off the pump or when terminating a process also flushing through the valve 44 respectively. In this case, according to the above procedure when switching off the suction-side valve is closed and the two valves 30 . 34 will be opened. In addition, the valves 44 . 46 open. A corresponding rinse takes place over a period of two to five minutes. After that, the valves 44 . 46 closed again. In the liquid separator 18 the rinse liquid collects, which can be displayed via a sensor, such as a liquifant, which is connected to the liquid separator. One in the lead 54 arranged valve can be opened to the liquid by means of the pump 56 pump out. Then this is in the line 54 existing valve closed again and the pump 56 turned off again. Should be in the liquid separator 80 collect no liquid, it is advantageous to generate a warning signal and / or a check of the level of the tank 50 make.

This is followed by dry running of the pump 10 with the suction-side valve still closed and the valves 30 . 34 are open over a period of 15 to 30 minutes. Then the pump can 10 be turned off, at the same time an exhaust valve, if it is present, can be closed. Furthermore, now the valves 30 . 34 closed. The pump is now back in start position.

Further Is it possible, while or to request monitoring parameters after the cleaning process. Should a value continue over the permissible Value, a new cleaning cycle can be carried out automatically.

Claims (17)

Method for cleaning vacuum pumps, having pumping elements arranged in a pump chamber formed by a housing, a container connected to the pump chamber ( 50 ) for providing a cleaning fluid, and at least one having a control device ( 38 ), comprising the steps of: detecting at least one pump parameter by the at least one sensor element, transmitting the pump parameter to the control device ( 38 ) for further processing in a monitoring program, and triggering of a cleaning program in which, in particular, time-controlled and / or quantity-controlled cleaning fluid is supplied to the suction chamber, as a function of at least one, in the control device ( 38 ) stored trigger parameters. The method of claim 1, wherein the at least one pump parameter, the temperature of individual components of the vacuum pump, in particular the housing, the pump elements, the drive motor ( 40 ) and / or a coolant of the vacuum pump, in particular the pump elements, and / or the pumped gas, in particular at the pumping chamber inlet ( 12 ) and / or at the pump chamber outlet ( 16 ). The method of claim 1 or 2, wherein the at least one pump parameter vibration or vibration of individual components of the vacuum pump, in particular the housing, the pump elements, and / or the drive motor ( 40 ). Method according to one of claims 1 to 3, wherein the at least one pump parameter, a gas pressure of the pumped gas, in particular at the suction chamber inlet ( 12 ) and / or at the pump chamber outlet ( 14 ). Method according to one of claims 1 to 4, wherein the at least one pump parameter has a barrier gas pressure and / or a Includes coolant pressure. Method according to one of claims 1 to 5, wherein the at least one pump parameter, the power consumption of the pump motor ( 40 ). Method according to one of claims 1 to 6, in which several pump parameters, in particular based on a diagnostic model, are linked to one another in the monitoring program. Method according to one of claims 1 to 7, in which different Cleaning programs, in particular depending on the pumped gas and / or the gas flow rate selectable and / or can be assembled. Method according to one of claims 1 to 8, wherein the Sequence of the cleaning program as a function of during the Cleaning process measured pump parameters is varied. Method according to one of claims 1 to 9, in which as Cleaning fluid at least one cleaning fluid and / or at least a purifying gas is preferably used the entrance to the pump room be mixed. Method according to one of claims 1 to 10, wherein the cleaning liquids chemical, biological and / or organic cleaning fluids , wherein different cleaning liquids preferably in different containers to be provided. Method according to one of claims 1 to 11, in which as Cleaning gases dry fluorine, fluorine compounds, nitrogen, nitrogen compounds and / or other active gases or gas mixtures are used. A method according to claim 11 or 12, wherein the mixing ratio the different cleaning fluids and / or the different cleaning gases dependent on that of the supervisor triggered Cleaning program selected is and preferably during the Expiration of the cleaning program, in particular depending measured pump parameter is controlled. Method according to one of claims 1 to 13, wherein the Cleaning fluid is used several times, in particular a cleaning fluid circuit consists. A method according to claim 14, characterized in that the cleaning fluid after flowing through the pump chamber again the supply container ( 50 ) is supplied. A method according to claim 14 or 15, wherein the cleaning fluid is particularly purified from solids. Method according to one of Claims 1 to 16, in which the quality of the cleaning fluid is determined in particular by means of one in the delivery container ( 50 ) arranged sensor is checked.